That Time Derek Got Jealous Without Cause
by A Fire in the Attic
Summary: "Derek, seriously," Erica sighs. "What is your damage?" Derek's only response is to look constipated.


**Prompt**: Derek finally tells Erica that she's his mate… in front of the entire pack… after hearing about what happened at the rave (Jerisaac threesome dancing), and her reaction

**Word Count**: 1570

**Pairings**: Derica, background pre-Stisaac

* * *

After the messiness with Scott and Victoria, it takes a nearly a week for Isaac and Erica to fully rehash what happened that night at the rave. They make reports to Derek in snippets during training sessions or in text messages sent when teachers aren't looking.

Erica wasn't going to mention grinding on both Isaac and Jackson just because it seems irrelevant. She's in possession of her own body, thanks, and while it had been nice, it's not like she feels the need to brag about it to her alpha. Which would be weird, okay? Derek is some cool older guy who could probably sleep with the entire town, if he felt like it.

(Erica suspects he does not feel like it, and would probably cry at least through the first ten people. But whatever, she's not worried about it.)  
But Isaac.

Isaac and Derek are weirdly intense around each other. It's not that she thinks they're banging (although if they are, she wouldn't mind being there, see?) but they often treat each other like…extensions of themselves. Like they're the same person.

Which is an apt assumption to make, she decides. They are both angry orphans who turn to violence first. Plus there's the way they flirt to get what they want. (To be fair, Isaac's version of flirting is usually beating people up in front of Stiles. Then again, it usually works.)

The point, though, is that Isaac told Derek about all the gritty details of the rave. She has no idea when he even had time to sit down and explain about how she distracted Jackson and managed to include Isaac in it. She has no idea why Isaac thought Derek needed to know. Maybe he feels violated by the whole experience? Whatever. Isaac can stop being such a pussy if that was the case.

Right now, Isaac has Boyd pinned against the wall, so…maybe he's not a complete pussy.

Derek, however, is glaring at her.

"Are you really that upset about it?" she huffs, exasperated. They're supposed to be sparring, and instead, Derek is asking why she acted the way she did at the rave. He literally asked that. "You told me to distract Jackson so Isaac could inject him with the stuff. So I did."

Derek huffs, crossing his arms. He's obviously trying to figure out how to say whatever it is without implying that she's a slut, or maybe he's just trying to find the most cryptic way to say whatever it is. Derek probably doesn't support the Freedom of Information Act.

"Derek, seriously," she sighs. "What is your damage?"

"You," he grits out, and then stops, running a hand over his face. It musses his eyebrows and she takes a long second to stare at that. Eyebrows shouldn't be hot. Derek Hale is out to knock down boundaries for eyebrows every where.

"Me," she prompts when it looks like Derek isn't going to continue. "Or maybe 'I.'"

"You are," he tries again, but ends up stopping and just staring at the ground.

"A good beta? A quick thinker?" she offers. "Really ridiculously good-looking?"

Ha! Victory. Derek is smirking, which is basically a full laugh from him. She'll take it.

"Yes, to all three," he says. "But I mean that you're my um…my mate."

"Your mate," she repeats blankly. To her left, Boyd flops to the ground because Isaac has turned to watch the impending blowup.

"Yes?" Derek says. He looks sufficiently worried.

Erica lifts her hands to her face and for a second, hides behind them. "What the hell does that mean?" she asks, voice muffled.

"Whatever you need it to," he offers.

"Is this like freaking Twilight?" she demands, dropping her hands. "You imprinted on me or some shit?"

"No! …A little bit," Derek answers.

"Why the hell did you throw me away, then?" she snarls, and punches him in the face hard enough that he stumbles back. "You. Don't. Own. Me," she tells him, punctuating her words with quick jabs to his abdomen. She kicks him hard and he falls backward. "Especially when you don't tell me his shit! Stop being butthurt that I flirted with other people when I didn't even know how you felt about me, you enormous douchenozzle."

She starts to walk away, fully intending on taking a dramatic exit, but then she spins on her heel and snaps, "Do you even have feelings or is this some compulsory bullshit? Because that shit don't fly."

"It's complicated," Derek says, from where he's still sprawled on the floor.

"Uncomplicate it, then," she replies tersely.

Isaac and Boyd are rapt with attention. Boyd is kind of smirking, the blood drying on his lips as he leans back against the hall. Isaac's knuckles are bloody. They look like they just walked off the set of Werewolf Fight Club.

Come to think of it, that's what this is. Damn it.

"You know what, I'm not dealing with this," she says, throwing up her hands. "Not right now. I have a test tomorrow and studying where my mom can bother me actually seems preferable to this. Bye."

Now she takes her dramatic exit, storming up the stairs and away from the train station.

She rescinds her earlier statement. Derek is not a cool older guy. He's a loser who would definitely cry during sex. She hates him.

"Erica?" Derek calls miserably from behind her. "Can I give you a ride home?"

"No," she says without turning around.

"Please?"

"No," she repeats.

"But—"

"Take no for an answer," she snaps.

He sighs, but goes back into the train station.

She feels some smug satisfaction in knowing he's trainable. She hums under her breath and thinks about making out with Scott to spite Derek.

* * *

The following day, Erica skips gym to go to the train station instead.

Derek is reading a book in the train car—or, he was, because when she walks in he just stares at her.

"So," she says, sitting down next to him. "Are you prepared to explain, yet, or should I start seducing Scott again? That's what you wanted, right?"

"That was…poorly done," he says, the tips of hears turning pink.

"Really," she says, acting irritated. In reality, she's delighted at the prospect of making Derek blush.

"When you kissed me, I—"

"You kissed me back," she breaks in. "Say, 'When we kissed…'"

Derek rolls his eyes. "When we kissed and I stopped you—"

"Threw me away."

Now he winces. "Um. Right. Well. I was hesitant to let anything happen given that you were fifteen at the time."

"Now I'm sixteen and that makes a difference?" she asks, disbelievingly.

"Not at all," he mumbles. "You're still too young. I wasn't going to say anything but I was upset about what happened at the rave, and you wanted to know why so I got flustered and ended up telling you anyway."

"You realize you haven't told me a damn thing," she says. She waits for him to supply information—any at all, really—but the silence stretches out until she's huffing and flopping into a more comfortable position on the train seat. It's not easy to find, actually, but she manages. "Did I skip gym for nothing?"

"Yes," he tells her, lifting his book again. "I'm not telling you anything until you're 18."

"You are such a loser," she sighs. "Entertain me."

"No."

"I hate you."

"You don't."

"Do so."

"Okay."

"Ugh, you suck."

"Go to school, Erica," he says.

She sits up straighter. "Don't act like my father. That is like the opposite of the way you should try to get into my pants."

Derek looks unimpressed.

"What would you do if I kissed you right now?" she asks curiously. "Throw me off again?"

He rolls his eyes and looks back at his book, but his hands grip the book tighter.

"I mean it's not like kissing is illegal," she points out. "Just the nudity and orgasms bit. Although we could probably keep that a secret, and you'd never have a problem with the sheriff." She pulls the book out of his hands. "I bet Stiles would cover for you."

Derek raises an eyebrow. "Erica…" he starts, sounding like he's going to scold her even as he leans toward her.

She grins when he kisses her instead of finishing his sentence. So she can get used to this. Derek might be her alpha, but this is her realm, she thinks as she pushes back against him until she's basically in his lap, fingers brushing over the back of his neck while she licks into his mouth. Derek is hers to command.

Like he can hear what she's thinking, he pulls away, leaning back so his head rests against the train wall. "Stop it," he says, frowning. "S'not fair."

"Your face isn't fair," she answers.

He laughs a little and his hands tighten on her hips, which…hmm…when did they get there? Not that she's complaining. "And you're five years younger than me. Stop."

"Ugh," she groans. "Fine. I'm leaving, then."

"Or you could stay," Derek suggests quickly. "We could…talk?"

"You hate talking," she says blankly.

"Do not."

"Do so," she says. "But, I'll let you buy me food, because I'm hungry. To the Batmobile!" She snags his keys from his pocket and hurries up the stairs to the Camaro.

Erica is going to get something out of this.

* * *

**A/N**: When I posted this on tumblr it didn't have a title and that's why this one is really lazily done but at the same time I like it so deal.

**Disclaimer**: I don't own anything. Like Teen Wolf and Twilight? They don't belong to me


End file.
